Breaking pattern and critical breaking condition of Japanese pine trees on coastal sand dunes in huge tsunami caused by Great East Japan Earthquake
Breaking pattern and critical breaking condition of Japanese pine trees on coastal sand dunes in huge tsunami caused by Great East Japan Earthquake
复制标题
东日本大地震海啸中沿海沙丘日本松的破坏模式及临界破坏条件
作者：
N. Tanaka;J. Yagisawa;S. Yasuda
海岸植被被广泛认为可以减少海啸对人和建筑物的破坏，最近人们对它进行了研究，因为与人工措施相比，它需要的资本投资相对较少，提供了对人类友好的海滩前沿，并加强了与其他生态系统的相互关系。然而，2011年3月11日14：46 JST的东日本大地震引发的海啸，震级为9.0，震中位于仙台以东129公里，破坏了大部分海堤（海啸门，大型海啸），并对日本东北和关东地区的沿海森林造成了灾难性的破坏。通过野外调查，阐明了日本海岸松的临界折断条件。当海堤被冲毁或没有海堤时，树木受到强大的惯性力或碎片的冲击力，树干会发生断裂。尽管树干弯曲和折断现象不同，但统计分析表明，树干弯曲和折断的临界直径没有很大差异。倾覆现象比树干折断稍微复杂一些，因为阻力是基底和根锚固的函数。根据海啸水深、土壤-根系强度和水动力参数（HD）的函数关系，推导了树干弯曲、折断和倾覆临界直径的计算公式，其中水动力参数（HD）由佛劳德数、阻力系数和冲击力与阻力之比组成，并考虑了抵御海啸的物理机制。树干弯曲和折断与海啸水深和水动力参数（HD）密切相关，但树木倾覆被发现更具现场特异性，根土强度极大地影响了临界值。建议的临界直径方程及其系数可用于设计内陆松树林，以捕获大树，汽车，碎片等，达到了极限在今后的内陆森林设计中，应更多地利用其诱捕功能，如有可能，应尽量利用其诱捕功能。
Coastal vegetation is widely recognized to reduce tsunami damage to people and buildings, and it has been studied recently because it requires relatively little capital investment compared with artificial measures, provides human-friendly beach fronts, and enhances inter-relationships with other ecological systems. However, the tsunami caused by the Great East Japan Earthquake at 14:46 JST on March 11, 2011, with a magnitude of 9.0 and epicenter 129 km east of Sendai, broke most of the sea wall (tsunami gates, large embankments) and caused catastrophic damage to coastal forests in the Tohoku and Kanto districts of Japan. A field survey was conducted to elucidate the critical breaking condition of Japanese coastal pine trees. Tree-trunk breakage was observed when the sea embankment was washed out or when there was no sea embankment and the tree was under strong inertia force or impact force by debris. Even though the trunk bending and breaking phenomena are different, statistical analysis showed that the critical diameters for trunk bending and trunk breaking were not very different. The overturning phenomenon is a little more complex than trunk breaking because the resistive force is a function of the substrate and root anchorage. An equation to determine the critical diameters for trunk bending, trunk breaking, and overturning was derived as a function of tsunami water depth, soil-root strength, and the hydrodynamic parameter (HD) formulated by Froude number, drag coefficient, and the ratio of impact force to drag force considering the physical mechanisms to resist the tsunami. Trunk bending and breaking were closely related to tsunami water depth and the hydrodynamic parameter (HD), but tree overturning was found to be more site specific, and the root-soil strength greatly affected the critical value. The proposed critical diameter equation and its coefficient are useful for the design of an inland forest of pine trees that can trap large trees, cars, debris, etc., to its breaking limit. The trapping function should be utilized more in the future designs of inland forests, if possible, on embankments.
TsuSedMod 反演模型应用于 2004 年苏门答腊岛和 2006 年爪哇海啸的沉积物以及对估计古海啸流动参数的影响
影响因子：
2.8
作者：
Spiske;Bahlburg;Roskosch;Amijaya
通讯作者：
Amijaya